In information theory, the entropy-power inequality (EPI) of Shannon
 and Stam  has played key roles in
the solution of several canonical network communication problems.
Celebrated examples include Bergmans's solution  to
the Gaussian broadcast channel problem, Leung-Yan-Cheong and
Hellman's solution  to the Gaussian wire-tap
channel problem, Ozarow's solution  to the Gaussian
two-description problem, Oohama's solution [1]} to the
quadratic Gaussian CEO problem, and more recently Weingarten,
Steinberg and Shamai's solution [2]} to the
multiple-input multiple-output Gaussian broadcast channel problem.
